LIQUID-LIQUID EQUILIBRIUM AND KINETICS OF ETHANOLIC EXTRACTION OF SOYBEAN OIL USING ETHYL ACETATE AS CO-SOLVENT

Abstract This work reports a new set of experimental data for the liquid-liquid equilibrium (LLE) of the system (soybean oil + ethyl acetate + anhydrous ethanol) and the kinetics of crude oil extraction from soybean flakes using anhydrous ethanol + ethyl acetate mixtures. Data for the LLE binodal were measured at 298.15, 313.15 and 333.15K by the cloud point method and tie-lines were obtained at 298.15 and 313.15 K. LLE data were successfully modeled using the NRTL model. Batch extractions were performed at 298.15, 313.15 and 328.15 K at a fixed (4:1) solvent to soybean flake mass ratio and two concentration of ethyl acetate (5% and 10%) in ethanol. Higher temperatures increased the solubility of the system and improved the extraction yields. In addition, higher ethyl acetate ratios in anhydrous ethanol led to an increase in the total amount of crude oil extracted when operating at 298.15 and 313.15 K. At 328.15 K, no improvement in extractions was verified when 5% and 10% of ethyl acetate were used in the ethanol. A mass transfer model based on Fick’s Law was applied to describe the extraction kinetics, presenting an average relative deviation of ± 5.11%, in terms of extraction yield.

摘要 本工作报道了（大豆油+乙酸乙酯（ethyl acetate）+无水乙醇（anhydrous ethanol））体系的液液平衡（liquid-liquid equilibrium, LLE）新实验数据集，以及采用无水乙醇与乙酸乙酯混合溶剂从大豆薄片（soybean flakes）中提取原油的动力学数据。采用浊点法在298.15、313.15和333.15 K下测得液液平衡双结点曲线数据，并在298.15和313.15 K下获取了联结线（tie-line）数据。采用NRTL模型成功对液液平衡数据进行了建模。分批萃取实验在298.15、313.15和328.15 K下开展，溶剂与大豆薄片的质量比固定为4:1，乙醇中乙酸乙酯的浓度设置为5%和10%两个水平。更高的温度可提升体系的溶解度，同时提高萃取收率。此外，在298.15和313.15 K下操作时，无水乙醇中乙酸乙酯占比更高会使提取的原油总量增加。而在328.15 K下，当乙醇中添加5%和10%的乙酸乙酯时，未观察到萃取效果的提升。采用基于菲克定律（Fick’s Law）的传质模型对萃取动力学进行描述，该模型的萃取收率平均相对偏差为±5.11%。